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Originally posted by dtlithonia1 I don't think it's a surface oil problem. I am still getting gallons of rust & sludge out of the system after I bring it up to steam.(running at 2.5 psi)

2.5 psi of steam?....remember, setting the pressure-trol to 2.5 is the cut-in pressure, the cut-out pressure is the differential setting plus the 2.5 psi. Typical pressure-trol setting on the diff is 1 psi, so in effect you could have 3.5 psi of steam pressure in the system....OUCH. That's ALOT of steam energy that is just aching to make noise and stir up alot of sludge. I'm no steam guru, so hopefully someone who is can proof read this. For a residential boiler I run maybe 1 psi of steam and set the diff really low, maybe .5 psi tops. Lower setting on the pressure-trol has got to save fuel too I would think.

The only way I can skim is to unscrew the pressure safety since its taped in near the top of the boiler into a 3/4" hole. Do I have to do this hot or cold? If I added vinegar to the water how much would I add and what would this do? Thanks. Oh the company that just put in the boiler is out of business.

make sure if you take the relief valve out to skim the boiler put a tee in and reinstall the pressure relief valve god forbid something was to happen to you and that boiler was operating without a relief valve you never know

My question now would be--- if I skimmed and flushed and was fairly sure there was no oil or dirt in the boiler but everytime the boiler tried to make steam it was still pushing water up the pipes (and of course bringing down dirt and rust) what would I do next?

Originally posted by dtlithonia1 I don't think it's a surface oil problem. I am still getting gallons of rust & sludge out of the system after I bring it up to steam.(running at 2.5 psi)

2.5 psi of steam?....remember, setting the pressure-trol to 2.5 is the cut-in pressure, the cut-out pressure is the differential setting plus the 2.5 psi. Typical pressure-trol setting on the diff is 1 psi, so in effect you could have 3.5 psi of steam pressure in the system....OUCH. That's ALOT of steam energy that is just aching to make noise and stir up alot of sludge. I'm no steam guru, so hopefully someone who is can proof read this. For a residential boiler I run maybe 1 psi of steam and set the diff really low, maybe .5 psi tops. Lower setting on the pressure-trol has got to save fuel too I would think.

The 2.5 would be the cut-out, minus differential for cut-in.
The problem with pressure controls is that there not very accurate, close though.

Noel is right about what-if's, without some certainty as to the water quality and the boiler internal condition it's speculation as to the issue.

One thing, if the water is hard it's most likly more on the acidic side.
A high PH will cause surging/foaming.
Oil will cause carryover, slight priming with lo pressures. The oil increases the water surface tension causing the steam bubbles to explode through the layer with much greater velocity. Oil in the water can be confused with a hi PH level and the two are often confused.

Also read that the guy is empting and re-filling with fresh water, a good idea, if possible, is to use not cold tap water but heated water. Cold water holds much more disolved oxygen than hotter water.
With residential this isn't always possible, but even 120 degrees from the hot water tank is better than cold tap water for a skimming.
The idea is to remove as much O2 as possible before steaming.

Hi thanks again Noel and to all who have helped. I spent two days surface skimming and the system is working much, much better. I skimmed untill the water looked clean enough to drink and a sample boiled quietly on the stove. But I'm still getting some surging and bringing new contaminents into the boiler and it looks like it will get worse after a period of use. I also set the pressuretrol to 2psi and the differential to one half pound. It says the differential is subtractive. That means the boiler should cut out at 2 lbs and back in at one half pound if I am still calling for heat. Is that right? Also someone suggested a boiler cleaning additive and someone else said never to use anything like that. All the radiators in the house now do get warm although I know I still have to do some balancing once I get rid of the surging. And I am still not sure the pressuretrol is set correctly. I can see by the pressure gauge that I am still getting a couple of pounds in the system even though the main vents and all the radiator vents are new.